A child pornography ring has been broken up in Spain, with 56 men arrested in police raids. This follows 18 months of investigations and the arrests took place over several months in provinces across the country.

The group's suspected leader was one of the men detained in several locations, mainly in Madrid and Barcelona, Spanish police said on Thursday.

The suspects - mainly Spanish and aged between 40 and 60 - are accused of sharing and distributing abusive images involving children on peer-to-peer internet file-sharing sites.Photos and videos from the "extremely serious abuse of very small children" category were among materials found by police, with 170 hard drives discovered, as well as 600 CDs and DVDs containing child pornographic material.

In August, Spanish police said they had broken up a child pornography ring, arresting seven people suspected of exploiting at least 80 minors over a 15-year period. Investigators found the ring had distributed "more than a million photographs and videos of child pornography and more than a thousand DVDs,” Spanish authorities said in a statement.Of those arrested, the majority were of French and Moroccan nationality.